In clinical practice some of the initially EGFR-TKI sensitive tumors which progressed evidence a striking increase in tumor volume within several weeks, after being taken off EGFR-TKI. This response is called "rebound phenomenon". Most experts still believe that these tumors continue to be "oncogene-addicted" to EGFR. So it is rational that EGFR-TKI combined with another chemotherapy regimen can be used to treat NSCLC after the failure of EGFR-TKI therapy.